Elevator system with car selection



April 21, 1970 H. c. SAVINO 3,507,363

ELEVATOR SYSTEM WITH GAR SELECTION :Filed Oct. 27, 1967 2 Sheets-Sheet l SYSTEM OF PATENT 3.256.958 WITH CHANGES PR2! a BFRZI'Q,"

MFCRI CFR2I RNSZI TSS-I TS4-2 l TS3-2 A ril 21, 1910 H. c. SAVYINOI 3,507,363 Y v ELEVATOR SYSTEM wrm CAR SELECTION I Filed Oct. 27, 1967 Y I 2 Sheets-Sheet "2 (CFCRZZ GD (BFCR22 (ID BFCRZS k FcR23 I WITNESSES VINVENTOR Henry C. Sovino %+4 5 v l ffiwl ATTORNEY 3,507,363 ELEVATOR SYSTEM WITH CAR SELECTION Henry C. Savino, Hackensack, N.J., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 27, 1967, Ser. No. 678,663 Int. Cl. B66b N24 US. Cl. 187-29 18 Claims ABSTRACT OF THE DISCLOSURE An elevator system has a number of landings divided into zones and several elevator cars. Each elevator car under certain conditions is available for assignment to any of the zones. When a demand for service is registered the nearest available elevator car is selected to respond to the demand. Provision also is made to select the closest elevator car to proceed to the lowest of several up demands in the zone.

FIELD OF THE INVENTION This invention relates to vehicular systems employing several vehicles and it has particular reference to a system wherein the most desirable of several vehicles is selected to respond to a demand for service.

Although aspects of the invention are applicable to various vehicular systems such as those providing horizontal transportation, it is particularly suitable for vertical transportation systems and will be described as applied to an elevator system.-

DESCRIPTION OF THE PRIOR ART In elevator systems several elevator cars may be available to answer a demand for service. Under such circumstances, one of the elevator cars may be selected for assignment to answer the demand. It has been proposed that a stepping switch be employed for making this selection. The stepping switch may be arranged to step away from a position corresponding to the location of the demand until it reaches an elevator car available for answering the demand. A stepping switch is shown in the French Patent 769,613 which was granted June 11, 1934. Such a system not only is costly but lacks flexibility.

In the Savino et al. Patent 3,256,958 stepping switches also are employed in the selection of an elevator car to respond to a demand.

SUMMARY OF THE INVENTION In accordance with the invention a logic system is employed for selecting an elevator car to answer a demand for service. Although solid-state or static components may be employed in the system electromechanical relays are readily incorporated in the system.

When a demand for elevator service is registered for a zone of a building, the system first interrogates such zone for the purpose of determining whether an elevator car in the zone is available to answer such demand for service. If an elevator car is available in such zone it is selected to answer the demand for service.

If no elevator is available in the zone of the demand logic elements such as electromechanical relays operate to transfer the interrogation to the neighboring zone or zones. This transfer continues until an available elevator car is located.

In certain cases it may be desirable to interrogate first a zone other than the demand zone. For example if a demand is registered for a main zone such as one including a street landing in a building having a basement zone, it may be preferable to interrogate the basement zone first for the presence of an available elevator car.

7' United States Patent "ice It is therefore an obect of the invention to provide an elevator system having simple logic circuits for selecting an available elevator car to answer a demand for service.

It is also an object of the invention to provide a systemas described in the next preceding paragraph which is designed to select substantially the nearest elevator car available to respond to the demand.

BRIEF DESCRIPTION 'OF THE DRAWINGS Other objects of the invention-will be apparent from the following description taken in conjunction with the accompanying drawings in which FIGURE 1 is a schematic view showing a portion of an elevator system embodying the invention, and

FIG. 2 is a schematic view showing additional circuits employed in a system embodying the invention. FIG. 2 may be placed below FIG. 1 to form a resultant schematic view.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to simplify the presentation of the invention, the following description will be based on the system shown in the aforesaid Savino et al. Patent 3,256,958. The conventions employed in such patent are utilized in the following discussion.

The circuits added for the present invention include a number of relays which are shown in the aforesaid Savino et al. patent. It will be understood that contacts may be added to such relays. For convenience such relays are listed as follows with an asterisk denoting those relays which are specific to the car A, the remaining relays being common to all of the cars:

DUH-high up zone demand relay DULlow up zone demand relay FCR-demand response relay* FRavailable car relay* FZl, FZ2, FZ3, etc.zone relays K0, K1, K2, etc.down zone demand registering relays Nnext car relay* RNS-no scan relay Z1, Z2, Z3, etc.zone position relays* 2UR, 3UR,4UR, etc.up floor call registering relays Additional relays which are employed in the present system include the following:

MFCRmaster relay TSB, T50, T51, etc.interrogation transfer relays TSNauxiliary transfer relay The selection circuits are energized from a suitable source of direct current represented by a positive bus L1 and a negative bus L2.

Each of the elevator cars has associated therewith a demand response relay which when picked up selects the associated elevator car to answer a demand for service. Inasmuch as three elevator cars A, B and C are employed for illustrative purposes their respective demand response relays FCR, BFCR and CFCR are shown. When one of these relays is picked up it operates in the manner set forth in the aforesaid Savino et al. patent to assign the associated elevator car to answer the demand for service.

Each of the demand response relays has its coil connectd between a separate auxiliary bus and the negative bus L2 through a rectifier and make contacts of the associated available car relay. Thus for the car A the coil of the demand response relay FCR is connected between the auxiliary bus LN and the negative bus L2 through a rectifier RE21 and make contacts FR23 of an available car relay FR which is shown in the aforesaid Savino et al. patent. The rectifier RE21 is poled to transmit current from the auxiliary bus LN towards the negative bus L2.

When the demand response relay FCR picks up it closes make contacts FCRZZ to establish with the make contacts FR23 a holding circuit. Consequently, when it picks up the demand response relay FCR remains picked up until the contacts FR23 open to indicate that the elevator car A is no longer available. When any of the demand responserelays (e.g. FCR) picks up it closes make contacts (e.g. FCR23) to pick up the master relay MFCR.

When any of the demand response relays is to be picked up, not only must the associated elevator car be available, but the associated auxiliary bus LN, BLN or CLN must be connected to the positive bus L1. The circuits for controlling such connection now will be considered.

The selection circuits in FIG. 1 are arranged for a building having a main zone, six zones above the main zone a basement zone below the main zone, each zone having one or more landings or floors. Inasmuch as the aforesaid Savino et al. patent shows a system suitable for a building having a main zone and three zones above the main zone it will be assumed for the present that the upper three zones in FIG. 1 are not employed (switch SW21 is open) and that the basement zone is not employed (switches SW23 and SW24 are closed).

When a elevator car is to be selected an auxiliary bus LNA is connected to the positive bus L1. This connection may be elfected if one of the elevator cars is available (make contact FR21, BFR21 or CFR21 are closed) if no elevator car is currently under selection (master relay break contacts MFCRI are closed) and if no basement service is required (break contacts 69P3 1 are closed). As described in the aforesaid Savino et al. patent if a demand is registered for a specific zone one of the zone relays FZO', FZl, etc. is picked up. For present purposes, it will be assumed that the zone relay FZ1 is picked up to close its make contacts FZ1-21. This prepares the demand response relays FCR, BFCR and CFCR for energization from the positive and negative buses respectively through the make contacts 21-21, BZ1-21, and CZ1-21, of the zone position relays Z1, BZ1 and CZ1 which are described in the aforesaid Savino et al. patent. For example, if the elevator car A is positioned and available in the first zone, the make contacts Z1-21 and FR21, F'R23 are closed to complete the following circuit L1, 6931, MFCRl, FR21, LNA, FZ1-21, Z1-21, LN, RE21, FR23, FCR, L2. This completes an energizing circuit for the demand response relay FCR of the elevator car A which is assumed to be available in the first zone. Consequently, the elevator car A is selected to answer the first zone demand. 1

If no elevator car is available in the demand zone, the interrogation is transferred to a neighboring zone or zones. For this purpose, when each zone is interrogated for an available car, an interrogation transfer relay is energized. For example, when the first zone is interrogated, following closure of the make contacts FZ1-21, the interrogation transfer relay TSl also is energized through the break contacts FCR-21, BFCR-21 and CFCRZl. This relay has a slight delay in pickup sufficient to permit prior interrogation of the first zone. If the elevator car A is available in the first zone the demand response relay FCR picks up to open its break contacts FCR21. This interrupts the energization of the interrogation transfer relay TS1 before such relay picks up. i

If no elevator car is available in the first zone at the time of interrogation, the interrogation transfer relay TS1 picks up to close its make contacts TS1-1 and TS1-2. The auxiliary bus LNA now is connected through the make contacts FZ1.21, TS1-2 and TS1-1 to interrogate the neighboring zones (switch SW22 is assumed to be closed).

The interrogation of zone 2 is similar to that of zone 1. Thus, if the elevator car B is located in the second zone, make contacts BZ2-21 of the zone position relay BZ 2 for the second zone are closed. (The numeral suffix in the reference character of a component indicates the zone with which such componentis associated.) Consequently if the car is available (contacts BFR21 and BFR23 are closed), the demand response relay BFCR is energized through the circuit L1, 69P31, MFCRl, BFR21, LNA, FZ121, TS1-2, BZ2-21B'LN, BRE21, BFR23, BFCR, FCR24, L2.

Interrogation at the main or zero zone may be similar to that for the zones previously discussed. However, as stated in the aforesaid Savino et al. patent, next relays N, BN and CN are employed for selecting the next car to leave the main floor. If a non-next elevator car is available at the main floor, when the interrogation takes place, it is preferable that such car 'be selected rather than the next car. For this reason break contacts of each next relay are connected in series with the make contacts of the associated zone position relay. For example, for the elevator car A break contacts N-21 of the next relay N are connected in series with the make contacts Z0-21 of the associated zone position relay Z0. Thus, if the elevator car B is selected as the next car to leave the main floor, and if the elevator car C is available at the main floor, the break contacts BN-21 are open and the break contacts CN-21 are closed. In addition,'the make contacts BZOt-21 and CZO-21 of the zone position relays are both closed. Under these circumstances, the elevator car C is selected to answer the first zone demand.

If no car is available, at the main floor, or in the second zone, the interrogation transfer relays TS2 for the second zone and T for the main floor zone pick up. Through its make contacts TS2-2 the interrogation transfer relay TS2 connects circuits for interrogating the presence of an available elevator car in the third zone in the same manner discussed for the first and second zones.

The interrogation transfer relay T50 closes its make contacts TSO-3 for the purpose of determining whether a next car is present at the main floor. (The switch SW-24 is assumed to be closed.)

Closure of the make contacts TSO-3 connects the auxiliary transfer relay TSN between the auxiliary bus LNA and the negative bus L2 through the circuit LNA, FZ1-21, T 81-1 or TSO-2, SW-24, TSO-3, TSN, FCRZI, BFCR21, CFCRZI, L2. If no basement zone is provided the TSN relay may be omitted.

In addition the closure of the make contacts TSO-3 completes a circuit for connecting any of the auxiliary buses LN, BLN and CLN through appropriate contacts, if closed, of the next relays and the zone position relays for the main floor to the auxiliary bus LNA. Thus, for the elevator car A, the auxiliary bus LN may be connected to the auxiliary bus LNA through the following circuit LNA, FZ1-21, TS1-1 or TSO-2, SW-24, TSO-3, N-22, Z0-22, LN. Therefore, if the elevator car A is selected as the next car to leave the main floor, if no other elevator car is at the main floor, and if no elevator car is available in the first, second and third zones, the elevator car A .is selected to respond to the first zone demand.

If the building served by the elevator system has six zones above the main floor the switch SW21.is closed to render efiective additional circuits for the zones 4, 5 and 6. The circuits for each of these zones are similar to those shown for the zone 2.

Let it be assumed that the switch SW21 is closed and that the interrogation has proceeded to the third zone and to the interrogation of circuits for the next cars at the main floor as above described. If no elevator car is selected as the result of such interrogation, the search continues upwardly successively through the fourth, fifth and sixth zones in a manner which will be clear from the preceding discussion.

Let it be assumed next that a long express zone is located between the main floor and the first zone. Under such circumstances it is desirable to interrogate zones above the express zone for an available. car before proceeding to an interrogation of the main floor. For such an installation the switch SW22 is opened to render effective make contacts of an interrogation transfer relay for the top zone. If the switch SW21 is open the top interrogation transfer relay is the relay T53, and the make contacts are designated ascontacts TS3-3.

With the switch SW22 open let it be assumed that a demand is registered for the first zone which results in closure of the make contacts FZ1-21. If no elevator car is available in the first zone, the interrogation cannot proceed downwardly to the main floor for the reason that the contacts TS33 are open. However, the interrogation proceeds upwardly in the manner previously. discussed until the interrogation transfer relay TS3 picks up to indicate that no available elevator car has been located above the express zone. In picking up this relay closes its make contacts TS3-3 to permit interrogation of the main floor in the manner previously discussed. Let it be assumed next that a demand is registered for the second zone (make contacts FZ2-21 are closed) that no car is available in the second zone, that the elevator car -A is available in the first zone and that the elevator car B is available in the third zone. Under these circumstances the interrogation starts in the second zone and then proceeds to the first and third zones. Inasmuch as the two available elevator cars are substantially equidistant from the demand it is satisfactory to permit either of the cars to respond to the demand.

If desired, a car may be arranged to respond in a predetermined order of priority. Thus, in FIG. 2, break contacts FCR24 of the demand response relay FCR are located between the coil of the relay BFCR and the negative bus L2. These break contacts together with break contacts BFCR24 of the demand response relay BFCR are both located between the coil of the demand response relay CFCR and the negative bus L2. When simultaneously energized, the relay FCR may be designed to pick up slightly before the relay BFCR and the latter relay may be designed to pick up slightly before the relay CFCR. Thus, under the assumed conditions the relay FCR would pick up to open its contacts FCR24 to prevent further energization of the relay BFCR and this would occur before pickup of the latter relay. Consequently the elevator car A would be selected to respond to the demand for service. Similarly, if the elevator cars B and C were available on opposite sides of a zone containing a demand for service and no elevator car was available in the demand zone, the elevator car B would be se lected. It will be understood that the demand response relays BFCR and CFCR have time delays in pickup which are less than the time delays of the interrogation transfer relays TSB and T86 and of the auxiliary transfer relay TSN.

.Let it be assumed next that the building served by the elevator system has a basement zone or floor and that the switches SW23 and SW24 are open. Single-pole double-throw switch SW25 is assumed to be moved-away from the position shownin FIG.-1 which renders contacts TSO-2 effective towards the right to render contacts -TSN1 effective. Zone position relays similar to those provided ifOI the other zones are provided for the basement zone and have make contacts respectively ZB21, BZB-21 and CZB21 for connecting respectively the auxiliary buses LN, BLN and CLN to the auxiliary bus LNA through make contacts FZO-21 of the zone relay for the main floor zone. The interrogation transfer relay TSB which is similar to the other interrogation transfer relays has its coil connected between the auxiliary bus LNA and the negative bus LT through the make contacts FZO-21 and the break contacts FCR21, BFCR21 and CFCR21 of the demand response relays for the three cars. When the interrogation transfer relay TSB picks up it closes its make contacts TSB-1. Until these contacts and TSO-3 close, a next car at the main floor cannot be selected. In addition, make contacts TSB2 close for the purpose of transferring interrogation-from the basement zone to. the first floor zone.

When a basement demand is registered the break contacts 69P31 open to prevent energization therethrough of the auxiliary bus LNA and the make contacts 69P32 close. If at the same time, an elevator car is available (make contacts FR22, BFR22 or CFR22 of the available car relays are closed) interrogation may proceed for the presence of an available elevator car at the basement floor. The basement demand relay 69P may be similar to one identified by the same reference character in the copending Savino et a1. patent application Ser. No. 220,522 filed Aug. 30, 1962.

Let is be assumed that the elevator car A is available (contacts FR22 are closed) in the basement zone (contacts ZB-21 are closed) and that a basement demand is registered (make contacts 69P32 are closed). This selects the elevator car A to answer to the base ment demand by the following circuit: L1, FR22, 69P32, ZB21, LN, RE21, FR23, FCR, L2. The relay FCR also opens its break contacts FCR21 to deenergize the interrogation transfer relay TSB. When the elevator car A loses its availability, the contacts FR23 open to deenergize the demand response relay FCR. The relay FCR then recloses its break contacts FCR21 and opens its make contacts FCR23 to deenergize the master relay MFCR. The master relay MFCRl recloses its break contacts MFCRl. The assignment of the elevator car A to answer the basement demand also results in closure of the break contacts 69P31 and opening of the make contacts 69P32. The system now is ready to make another selection.

Let it be assumed that instead of being available in the basement zone the elevator car A is available in the first zone (make contacts Z1-21 are closed and contacts ZB-21 are open). It will be assumed further that no other car is available. Under these circumstances, closure of the make contacts 69P32 energizes the interrogation transfer relay TSB for a period longer than the relay time delay. At the end of its time delay in pickup this relay closes its make contacts TSB-1. Such closure has no immediate effect on the operation of the system. In addition, contacts TSB2 close to transfer the interrogation to the main floor zone and to energize the interrogation transfer relay T50. If a non-next car is available at the main floor such interrogation would result in pickup of the demand response relay for such available car. However, since no non-next car is available at the main floor, the transfer relay TSO ultimately times out and closes its make contacts TSO-1, TSO2 and TSO-3. Contacts TSO-3 close to establish an interrogation of next cars available at the main floor through the contacts TSB-1. Closure of the make contacts TSO-1 has no effect on the operation of the system since contacts TSB-2 are already closed. ontacts TSO2 are ineffective since switch SW25 makes contact with TSN-l.

Since there is no next car to be selected, transfer relay TSN picks up through contacts TSB-1 and TSO-3. Closure of contact TSN1 transfers the interrogation to the first zone through the switch SW25.

Inasmuch as elevator car A is assumed to be available in the first zone, the demand response relay FCR now is picked up and operates in the manner previously described to assign the elevator car A to the basement demand and to restore the selecting circuits for further operation. Had no elevator car been available in the first zone, the interrogation would proceed upwardly zone by zone until an available car is reached for assignment to the basement demand.

When the basement zone is present, an available car in the basement zone is selected in preference to a next car at the main floor. Let it be assumed that a demand is registered for the first zone (contacts FZ1-21 are closed) that no available car is present in the first zone and that the interrogation has been transferred to the second and main floor zones. It will be assumed further that the elevator car A is available in the basement zone and that the elevator car B has been selected as the next car to leave the main floor (contacts BN-22 are closed). Under the assumed conditions, no elevator car is available in the second zone and no non-next elevator car is available at the main floor. When the interrogation transfer relay TSO times out it closes its make contacts TSO-2 and TSO-3 without immediate effect on the operation of the system. However, closure of the make contacts TSO-1 transfers the interrogation to the basement zone. It will be understood that at .the same time the interrogation is transferred to the third zone. However, it is assumed that no elevator car is available in the third zone.

Inasmuch as the elevator car A is available in the basement zone (make contacts ZB-21 are closed) the elevator car A is now selected to answer the first zone demand by a sequence which will be clear from the preceding discussion.

Had no elevator car been available in the basement zone, the interrogation transfer relay TSB finally would have timed out to close its contacts TSB-1 and TSB-2. This transfers the interrogation to the next cars available at the main floor. Inasmuch as it has been assumed that the elevator car B is selected as the next car to leave the main floor (contacts BN22 and BZO-22 are closed) this car is selected to answer the first-zone demand by a sequence which will be clear from the preceding discussion.

If the selected elevator car is to run to the highest of several demands for down service make contacts RNS21 are closed to connect a circuit containing the break contacts K1-22 to K6-22 arranged in the order of their zones to the auxiliary bus LNA. The relays for operating these contacts are described in the aforesaid Savino et al. patent. Make contacts of the down zone demand registering relays are employed for controlling the connections of the interrogating circuits to the auxiliary bus LNA. The interrogating circuits for each zone above the basement are connected to the auxiliary bus LNA through the make contacts RNS21 of the no scan relay RNS, through the make contacts of the down zone demand registering relay K etc. for the specific zone under con sideration and through break contacts of all the down zone demand registering relays for zones above the specific zone under consideration. For example, the circuit for the interrogating transfer relay TSl for the first zone may be traced from the auxiliary bus LNA through the contacts RNS21 the break contacts K622 to K2-22 of the down zone demand registering relays for the sixth to second zones inclusive, the make contacts K1-21 of the down zone demand registering relay for the first zone, the coil of the relay T81 and the break contacts FCRZI, BFCR21 and CFCRZI to the negative bus L2.

In order to illustrate the operation of this circuit, let it be assumed that down zone demands are registered for the first and second zones (break contacts K2-22 and K1- 22 are open and make contacts K1-21 and K2-21 of the down zone demand registering relays for the first and second zones are closed), that an available car A is present (make contacts FR21, FR22 and FR23 are closed) and that such available car is located at the first zone (make contacts Z1-21 are closed). Under such circumstances an interrogating circuit is established for the second zone as follows: L1, 69P31, MFCRl, FR21, LNA, RNS21, K622, K-22, K4-22, K3-22, K2-21, T52, FCR21, BFCR21, CFCR21, L2. This circuit checks for the presence of an available car at the second zone in the manner previously described. Inasmuch the the break contacts K2-22 are open an interrogating circuit cannot be established at this time for the first zone even though a down zone demand is registered for such zone.

Inasmuch as an available car is not located at the second zone, the interrogating transfer relay TS2 finally times out and transfers the interrogation to the first and third zones. Under the assumed conditions, the elevator car A is available at the first zone and the elevator car A is selected to proceed to answer the down zone demand. In this way, the system selects an available car closest to the highest down zone demand.

In order to illustrate the treatment of registered up floor calls, it will be assumed that the switch SW21 is closed and that each of the zones representsa single landing or floor. For the purpose of answering registered up floor calls, the fioors are divided into several up zones. In a preferred arrangement, two up zones are employed. The lower 'up zone includes the floors 1, 2 and 3 whereas the upper up zone includes the floors 4 and 5 (the floor 1 is assumed to be above the main floors). A conductor TX1 is connected through make contacts of the lowest up floor call registering relay for the lower zone, in this case the make contacts 1UR21 and make contacts DUL21 of the low up zone demand relay DUL to the positive bus L1. Similarly a conductor TX4 is connected through make contacts of the lowest up floor call registering relay in the higher zone in this case the make contacts 4UR21 and the make contacts DUH21 of the high up zone demand relay DUH to the positive bus L1. Between these two circuits, break contacts of the up floor call registering relays for the lower zone floors are arranged in series in the order of the floors. The connection between the break contacts 1U R22 and 2lUR22- is also connected to a conductor TXZ through make contacts 2UR21 of the up floor call registering relay 2UR. Similarly, the connection between the break contacts 2U'R22 and 3UR22 is connected to a conductor TX3 through make contacts 3UR21 of the up floor call registering relay for the third floor.

A conductor TXS for the highest floor from which an up call may be registered is connected to the connection between the contacts DUH21 and 4'UR21 through make contacts or such highest floor, in this case make contacts 5UR21, and through break contacts of the up floor call registering relays for all lower floors of the higher zone, in this case only the break contacts 4UR22.

As shown in FIG. 1, the conductors TX1 to TXS are connected to establish energizing circuits respectively for the interrogating circuits for the first to fifth zones inclusive.

If several up floor calls are registered in a zone, the search for an available elevator car starts at the lowest floor in the zone for which an up floor call is registered. Let it be assumed that up floor calls are registered for the first and second floors (make contacts 1UR21 and 2UR21 are closed whereas break contacts IUR22 and 2UR22 are open). In addition, the make contacts DUL21 are closed to initiate a search for an available car in the low zone. The operation of the contacts DUL will be found in the aforesaid Savino et a1. patent. Inasmuch as the break contacts 1UR22 are now open the closed contacts DUL21 are effective for connecting only the conductor TX1 to the positive bus L1. The conductor TX1 energizes the interrogating circuits for the first floor. The search for an available car to answer the first floor up demand continues in the manner previously described until such available car is selected to answer the demand. In this way the search for a car to answer an up demand in a zone always starts at the floor corresponding to the lowest up call in the zone.

In a similar manner, if up floor calls are registered for the fourth and fifth floors in the high zone, the make contacts 4UR21 and =5UR21 of the up floor call registering relays for such floors are closed and the break contacts 4UR22 are open. Thus closure of the make contacts DUH21 for the-high zone-is effective only for connecting the conductor TX4 for the lowest floor in the high zone for which an up floor call is registered to the positive bus L1. This starts. a search for an available car at the lowest in the high zone for which an up floor call is registered.

I claim as my invention: Y

1. A transportation system comprising a structure having landings arranged in plural zones each includingat least one separate landing, a plurality of vehicles each arranged for movement to serve said zones, each of said vehicles having a predetermined condition wherein such vehicle is available for assignment to anyone of said zones, demand means for each of said zones, each of said demand means being operable from a first to a second state to indicate a demand for service for the associated zone, and selecting means for selecting one of said vehicles to respond to a demand registered by one of said demand means, said selecting means comprising position means for each of said vehiclesfor each of said zones, each of said position means being operatble from a first to a second state to indicate presence of the associated ve: hicle in the associated zone, interrogating means for first interrogating the position means for a zone to determine the presence of an available one of the vehicles in such zone, plural electroresponsive transfer devices each associated with a separate one of the zones, each of the transfer devices being responsive to the interrogating means and the absence of said vehicles from the interrogated zone for transferring the interrogating means to interrogate the position means for a neighboring zone for the presence of an available vehicle in the neighboring zone.

2. A system as claimed in claim 1 wherein the transferring of the interrogating means is efiective to interrogate the position means for the neighboring zones on each side of said first interrogated zone for the presence of an available vehicle in said neighboring zones.

3. A system as claimed in claim 1 wherein said interrogating means is eifective in the presence of simultaneous demands registered by the demand means of plural zones for first interrogating the zone having such a registred demand furthest removed from a predetermined one of said landings.

4. A system as claimed in claim 1 wherein said interrogating means is effective only in the presence of an available one of said vehicles and of a demand registered by the demand means for performing said first interrogating.

5. A system as claimed in claim 2 wherein said landings include a first landing, a second landing, a third landing intermediate the first and second landings and a plurality of zones intermediate the second and third landings, said transfer devices being effective following said first interrogating fora zone intermediate the second and third'landings, provided no available vehicle is located, for transferring the interrogation successively to pairs of zones on opposite sides of the first-interrogated zone until the interrogation reaches the zone containing one of the second and third landings, and thereafter successively to the remaining zones between the second and third landings, said interrogating means being effective for interrogating the zone containing the first landing only after all zones containing the second and third landings have been interrogated.

-6. A system as claimed in claim 1 wherein said landings include a first landing, a second landing, a third landing intermediate the first and second landings and a plurality of landings intermediate the second and third landings, said interrogating means following interrogation of a zone intermediate the second and third landings being effective for interrogating a zone containing the first landing only after all zones between the second and third landings have been interrogated.

7. A system as claimed in claim 1 wherein said landings are floors of a building spaced vertically from each other and including a basement floor, a main floor located above the basement floor and additional floors located above the main flloor, said vehicles being elevator cars arranged for vertical movement; means for selecting the next vehicle to leave the main floor, said interrogating means in response to a demand registered by the demand means for the basement floor being eifective for selecting an available vehicle in the following order:

(a) an available vehicle in the zone including the basement floor,

(b) a non-next vehicle at the main floor,

(c) a next vehicle at the main floor,

(d)- the nearest avaliable vehicle above the main floor.

8. A system as claimed in claim 1 wherein said landings are floors of a building spaced vertically from each other and including abasement floor, a main floor located above the basement floor and additional floors located above the main floor, said vehicles being elevator cars arranged for vertical movement, means for selecting the next vehicle to leave the main floor, said interrogating means including means for interrogating the position means for the zone including the basement floor prior to interrogation of position means associated with the next vehicles at the main floor, and for thereafter interrogating the last-named position means if no available vehicle is located at the zone of the basement floor.

9. A system as claimed in claim 8 wherein said interrogating means in response to a demand from the zone including the main floor initially interrogates the position means for the zone including the basement floor.

10. A transportation system comprising a structure having a plurality of landings arranged in a plurality of zones each containing a plurality of landings, a plurality of vehicles each arranged for movement relative to the structure to serve the zones, each of the vehicles having a predetermined condition wherein such vehicle is available for assignment to any one of said zones, demand means for each of said landings, each of said demand means being operable from a first state to a second state to register a demand in a first direction for service for the associated landing, and selecting means for selecting any of said vehicles to respond to a demand registered by one of said demand means, said selecting means comprising position means for each of said vehicles for each of said landings, each of said position means being operable from a first to a second state to indicate presence of the associated vehicle adjacent the asociated landing, interrogating means responsive to operation of plural demand means in any of said zones for first interrogating the position means for the furthest of the landings in the second direction in the zone of such operated demand means which has an operated demand means.

11. A system as claimed in claim 1 wherein each of said transfer devices comprises a relay device, alteration means responsive to operation of one of said demand means and presence of an available one of said vehicles for altering the energization of the associated relay device for the purpose of changing the state of the relay device with time delay, interrupting means responsive to operation of the interrogating means upon detection of position means representing an available one of the vehicles for interrupting the alteration in energization of the relay devices for the relay device associated with the last-named position to prevent transfer of the interrogating means, and means responsive to such detection for assigning the last-named vehicle to respond to the operated demand means.

12. A system as claimed in claim 11 wherein said landings represent vertically-spaced floors of a structure and said vehicles are elevator cars, in combination with means responsive to operation of a plurality of said demand means for applying said alteration to the relay device which corresponds. to the furthest landing in one direction for which a demand means is operated.

13. A system as claimed in claim 12 wherein separate circuit means is controlled by each of said relay devices for applying said alteration in energy of the relay devices for one of the zones after said time delay to the relay device for an adjacent one of the zones.

14. A system as claimed in claim 13 wherein each of said demand means comprises a demand relay having first contacts which are operated from closed to open condition and second contacts which are operated from 111 open to closed condition in response to occurrence of a demand for service in the associated zone; each of said relay devices being connected for energization through the second contacts for the associated zone and through the first contacts in series associated with all zones above such associated zones.

15. A system as claimed in claim 14 wherein the lowest of said zones is a main zone and wherein said structure has a basement zone located below the main landing, demand means for said basement zone, said select ing means including position means for the basement zone, a transfer device for said basement zone comprising a relay device, alteration means for the basement zone responsive to operation of the associated demand means and presence of an available one of the vehicles for altering the energization of the basement relay device for the purpose of changing the state of the basement relay device with time delay, said basement relay device being connected for energization through the second contacts for the main zone, and through the first contacts for all zones above the main zones.

16. A system as claimed in claim 15 wherein each of said demand means for zones above the basement zone is for service in a down direction, up demand means for each of the intermediate ones of said zones operable for 12 registering a demand for up service, and up circuit means responsive to operation of any of the up demand meaps for effecting said alteration of the relay device associated with the zone of the operated up demand means.

17. A system as claimed in claim 16 wherein said up circuit means in response to operation of a plurality of the up demand means effects said alteration of the'relay device associated with the lowest of the zones having an operated up demand means. v

18. A system as claimed in claim 17 wherein the main zone is spaced from the next higher zone by an express zone, the relay device for the highest zone having contacts preventing interrogation of the main zone by the interrogating means in response to operation of one of the demand means for a zone above the express zone until the highest zone has been interrogated and the relay device for such highest zone has operated.

References Cited UNITED STATES PATENTS 3,781,107 4/1968 Madison 18729 B.- DOBE'CK, Primary Examiner 25 W. E. DUNCANSON, JR. Assistant Examiner 

